This is ^NON

^NON je ...

An anonymous identity provider for accessing services from NoLog.

No account saved in browser. You can create one by signing into a service.

Account saved in browser. Forget?

How does it work?

^NON [anon] creates your identities for different services based on an account code, which you can generate during login. Each service gets a different identity, so nobody can connect data between them. You, on the other hand, can connect to all of them using only a single account code.

You can check out the technical details here.